Effect of inactivation of genes involved in ammonium regulation on the biohydrogen production of Rhodobacter capsulatus

Gülşah Pekgöz, Ufuk Gündüz, Inci Erolu, Meral Yücel, K. Kovács, G. Rákhely

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Hydrogen production by nitrogenase is an energetically expensive process for the cell, hence strictly controlled at different levels. Ammonium is one of the substances regulating nitrogenase activity. The key proteins in the regulation of nitrogenase by ammonium are two regulatory proteins; GlnB and GlnK. In order to increase hydrogen production of Rhodobacter capsulatus DSM1710 (wild type strain) grown on agricultural materials/wastes, ammonium inhibition of nitrogenase enzyme has to be eliminated. In this study, GlnB and GlnK were targeted to be inactivated by in frame site-directed mutagenesis. The glnB mutant R. capsulatus (GP1 strain) was obtained at the end of mutagenesis studies. In the case of glnK, the suicide vector was constructed and delivered into the cells. However, glnK mutant could not be obtained. The effect of ammonium on the growth and hydrogen production of R. capsulatus GP1 was investigated and compared with DSM1710. Both DSM1710 and GP1 strains were effectively utilized acetate. The mutation did not affect cell growth significantly at different ammonium levels. Ammonium negatively affected hydrogen production of GP1 strain as well as the DMS1710. However, hydrogen production was significantly low in GP1 strain. The ammonium inhibition of hydrogen production could not be removed in glnB mutant probably due to the presence of an active GlnK protein in the cell. Therefore, GlnK has much more important role in the ammonium dependent control of nitrogenase than GlnB does. The growth and hydrogen production kinetics of R. capsulatus DSM1710 and GP1 were modelled. They were shown to fit to Logistic Model and Modified Gompertz Model, respectively.

Original languageEnglish
Pages (from-to)13536-13546
Number of pages11
JournalInternational Journal of Hydrogen Energy
Volume36
Issue number21
DOIs
Publication statusPublished - Oct 2011

Fingerprint

hydrogen production
Hydrogen production
genes
deactivation
Genes
mutagenesis
Mutagenesis
proteins
Proteins
cells
Enzyme inhibition
logistics
Cell growth
mutations
Logistics
enzymes
acetates
Enzymes
Kinetics
kinetics

Keywords

  • Ammonium inhibition
  • Biohydrogen
  • GlnB/GlnK proteins
  • Kinetic modelling
  • Rhodobacter capsulatus
  • Site-directed mutagenesis

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

Cite this

Effect of inactivation of genes involved in ammonium regulation on the biohydrogen production of Rhodobacter capsulatus. / Pekgöz, Gülşah; Gündüz, Ufuk; Erolu, Inci; Yücel, Meral; Kovács, K.; Rákhely, G.

In: International Journal of Hydrogen Energy, Vol. 36, No. 21, 10.2011, p. 13536-13546.

Research output: Contribution to journalArticle

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